This application seeks partial support for the Federation of American Societies of Experimental Biology (FASEB), conference on Yeast Chromosome Structure, Replication, and Segregation to be held July 25-20, 2012 in Steamboat Springs, Colorado. This will be the twelfth bi-annual iteration of what has become the most successful and important meeting for this field. This conference aims to join investigators studying many diverse aspects of chromosome biology and cell biology in the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe, using a range of experimental approaches including genetics, cytology, biochemistry, molecular biology, genomics, and systems biology. Presentations will introduce new and unpublished work on timely questions in the field and will include discussion from all participants. The FASEB conference provides unique opportunities for the exchange of information and technology that can be appreciated and exploited for studies of chromosome biology in more complex experimental organisms and in humans. Environmental agents - including manmade air- and water-borne pollutants, electromagnetic radiation, and nicotine and other natural products - can have profound effects on the replication, segregation, and repair of chromosomes. Moreover, an organism's environment has a strong impact on gene expression patterns. As such, chromosomes are a critical target through which the environment exerts toxic, mutagenic, and carcinogenic effects. The cellular processes that maintain genome integrity in the face of insults from environmental and endogenous sources are thus of fundamental importance for human health and disease. Many critical questions in these areas remain unresolved, and yeasts are outstanding model organisms for addressing these questions because of the evolutionary conservation of many of the molecular mechanisms and proteins involved. Much of the conference will thus be devoted to topics firmly within the mission of the National Institute of Environmental Health Sciences. In addition, chromosome instability is a prominent feature of both cancer and aging, and genome-destabilizing agents are at the same time causes of cancer and components of anti-cancer chemotherapies. Furthermore, changes in chromosome behaviors accompany normal cellular and organismal aging and contribute to age-related pathologies, and human genetic diseases associated with aberrant DNA metabolism are often accompanied by hallmarks of premature aging. Yeasts have long played a dominant role in studies of the fundamental mechanisms underlying normal and pathological chromosome dynamics, thus the topics covered in this conference also support the missions of the National Cancer Institute and the National Institute on Aging. PUBLIC HEALTH RELEVANCE: The faithful duplication, segregation, and repair of chromosomes are essential for normal growth of cells and thus for human health. The toxicity and/or carcinogenicity of many environmental agents are exerted through deleterious effects on these fundamental aspects of chromosome function, and chromosome defects underlie many aspects of cancer and aging. Because these processes are evolutionarily conserved, the relatively simple yeasts have proven to be enormously valuable model organisms for understanding normal chromosome behaviors as well as the environmental factors that perturb them. This conference brings together the principal investigators studying chromosome biology in yeasts.